Water bills higher than usual? You may have a leak.

Act now to cut your costs and save water.

Water leaks can occur unexpectedly and can be very costly to your business. Use our helpful FAQs below to help find out if you have a leak – and what to do about it.

Why are my water bills higher than usual?

If your water bills are becoming more expensive, and you are using more water than usual, this may mean that you have a leak. If this leak is on your premises, you are responsible for finding and repairing it.

How can I find out if I have a leak?

If you think you have a leak, you can follow these simple steps:

  • Choose a time of day where you can turn off all water appliances, for example overnight when your business is closed.
  • Then, if the meter is safe to access, take a meter reading.
  • Leave appliances off for at least 30 minutes, then take a meter reading again.
  • If the number has not changed, it is unlikely that you have a leak.
  • If the number has changed, you may have a leak.

Is it my responsibility to fix the leak?

Where your leak is located and identified will determine who is responsible for fixing it. As leaks can occur on pipeworks or fittings, you should read the tables below to identify who is responsible.

Who owns and is responsible for pipework?

Leak Diagram


Water Mains

Property owners land
Land owned by someone else 

Water wholesaler

Communication Pipe


Water wholesaler

Supply pipe serving a single property

Property owners' land
Land owned by someone else

Property owner
Share supply pipe serving more than one property Motorway
Land owned by any of the property owners served by the pipe
Land owned by someone else 
Joint responsibility of all property owners supplied by the pipe

Who owns and is responsible for fittings?

Sometimes leaks will occur directly on fitted assets. Dependant on the exact leak location and assuming no negligence from another party, either the Customer or Wholesaler will be responsible for repairs.


Stop tap including chamber and cover

Motorway Water wholesaler

Stop tap including chamber and cover

Within boundary of eligible premises Customer (Wholesaler if within 1 meter of boundary)

Stop tap including chamber and cover

Inside a building

Water meter including chamber
and cover and meter unions
Motorway Wholesaler
Water meter including chamber
and cover and meter unions
Within boundary of eligible premises Wholesaler
Water meter and meter unions Inside a building Wholesaler

I have a leak that is my responsibility. What should I do now?

To fix a leak, you can carry out the following simple steps:

  • Castle Water has various framework partners, some of which can assist with sub-terrain leak detection if it's not clearly evident where the leak is coming from. If your local plumber is unable to find a leak above ground, please get in touch for referral.
  • Call a private plumber to repair your pipes or contact your water network owner.
  • Check your building and contents insurance policy – this may cover the repair.

Ready to find your leak?

Working with our partners, M & S Water Services, we can help pinpoint a leak and carry out any repairs necessary.

Leak Detection, Repair, and Assistance

What if my supply is shared?

If you have a shared water supply, you and the other party who share it are both jointly responsible for ensuring that the leak is fixed.

What if I don’t get the leak repaired?

If you don’t repair the leak, your Water Network Owner has the right to fix the leak under Section 75 of the Water Industry Act 1991 and charge you directly for the repair. You will also be unable to claim for any allowance in most of these situations.

What if the leak is an emergency situation?

If the leak is an emergency, please contact your Water Network Owner. You can find contact details here.

Can I claim back the additional charges on my water bill?

You may be eligible to claim a leak allowance on your water bill, if the following has been met:

  • The supply is metered
  • All known leaks are repaired, and appropriate and sufficient evidence of the leak having been repaired is supplied upon application. This can be proven by either providing 2 reads two weeks apart after repair, or by providing a copy of the repair bill. Sufficient evidence is at the discretion of the network owner who grants the leak allowance to retailers.
  • The network owners policy covers your specific circumstances

Please note:

  • Only 1 allowance will be granted within any 24-month period, and any further requests will be granted at the discretion of the network owner
  • Exceptions to the above will be granted if a leak is confirmed the direct result of negligence on the part of the wholesaler
  • Leak allowance requests due to leaking internal fixtures and fittings or caused by vandalism will be rejected.
  • Any leak caused by negligence of the customer, retailer or a third party will not be granted

If you meet the above criteria, please complete our online leak allowance form.

The quickest way to apply for a leak allowance is through logging into MyAccount portal. Once logged in, Click here to submit your request and track its progress in the portal.

Alternatively, download and complete the attached PDF and upload it with our General Enquiry form here.

If you are a customer in Scotland, you do not need to complete the form. Simply email customersupport@castlewater.co.uk with your contact information and basic details of the leak and we will be in touch to guide you through the leak allowance process.